A catalyst for the polymerization of olefins made from or containing (a) a solid catalyst component containing Mg, Ti and optionally an internal electron donor compound (ID), (b) an aluminum alky compound, and (c) an external electron donor (ED) selected from non-aromatic diazo compounds.

A catalyst for the polymerization of olefins made from or containing (a) a solid catalyst component containing Mg, Ti and optionally an internal electron donor compound (ID), (b) an aluminum alky compound, and (c) an external electron donor (ED) selected from non-aromatic diazo compounds.

A solid catalyst component for the homopolymerization or copolymerization of olefins, made from or containing Ti, Mg, halogen, and at least one non-aromatic diazo compounds.

A solid catalyst component for the homopolymerization or copolymerization of olefins, made from or containing Ti, Mg, halogen, and at least one non-aromatic diazo compounds.

A process for preparing a catalyst component made from or containing Mg, Ti, and at least an electron donor compound (ID), including the steps of: (a) reacting a Mg based compound with a Ti compound, having at least a Ti—Cl bond, in an amount such that the Ti/Mg molar ratio is greater than 3 and at a temperature ranging from 0 to 150° C., thereby yielding an intermediate solid catalyst component containing Mg and Ti; and (b) contacting the intermediate solid catalyst component with a gaseous stream containing the electron donor compound (ID) in a gaseous dispersing medium, thereby yielding a final solid catalyst component having an ID/Ti molar ratio ranging from 0.5:1 to 20:1.

A process for preparing a catalyst component made from or containing Mg, Ti, and at least an electron donor compound (ID), including the steps of: (a) reacting a Mg based compound with a Ti compound, having at least a Ti—Cl bond, in an amount such that the Ti/Mg molar ratio is greater than 3 and at a temperature ranging from 0 to 150° C., thereby yielding an intermediate solid catalyst component containing Mg and Ti; and (b) contacting the intermediate solid catalyst component with a gaseous stream containing the electron donor compound (ID) in a gaseous dispersing medium, thereby yielding a final solid catalyst component having an ID/Ti molar ratio ranging from 0.5:1 to 20:1.

An ultra-high molecular weight, ultra-fine particle size polyethylene has a viscosity average molecular weight (Mv) greater than 1×10.sup.6. The polyethylene is spherical or are sphere-like particles having a mean particle size of 10-100 μm, having a standard deviation of 2-15 μm and a bulk density of 0.1-0.3 g/mL. Using the polyethylene as a basic polyethylene, a grafted polyethylene can be obtained by means of a solid-phase grafting method; and a glass fiber-reinforced polyethylene composition comprising the polyethylene and glass fibers, and a sheet or pipe prepared therefrom; a solubilized ultra-high molecular weight, ultra-fine particle size polyethylene; and a fiber and a film prepared from the solubilized ultra-high molecular weight, ultra-fine particle size polyethylene may also be obtained. The method has simple steps, is easy to control, has a relatively low cost and a high repeatability, and can realize industrialisation.

An ultra-high molecular weight, ultra-fine particle size polyethylene has a viscosity average molecular weight (Mv) greater than 1×10.sup.6. The polyethylene is spherical or are sphere-like particles having a mean particle size of 10-100 μm, having a standard deviation of 2-15 μm and a bulk density of 0.1-0.3 g/mL. Using the polyethylene as a basic polyethylene, a grafted polyethylene can be obtained by means of a solid-phase grafting method; and a glass fiber-reinforced polyethylene composition comprising the polyethylene and glass fibers, and a sheet or pipe prepared therefrom; a solubilized ultra-high molecular weight, ultra-fine particle size polyethylene; and a fiber and a film prepared from the solubilized ultra-high molecular weight, ultra-fine particle size polyethylene may also be obtained. The method has simple steps, is easy to control, has a relatively low cost and a high repeatability, and can realize industrialisation.

An injection molded article made from or containing a propylene-based composition made from or containing: T1) from 90 wt % to 50 wt % of a propylene homopolymer; and T2) from 10 wt % to 50 wt % of a polymer composition made from or containing A) 5-35% by weight of a propylene homopolymer or a propylene ethylene copolymer; B) 20-50% by weight of a copolymer of ethylene and a C.sub.3-C.sub.8 alpha-olefin containing from 0.1% to 20% by weight of alpha-olefin units; and C) 30-60% by weight of a copolymer of ethylene and propylene containing from 25% to 75% by weight of ethylene units.

An injection molded article made from or containing a propylene-based composition made from or containing: T1) from 90 wt % to 50 wt % of a propylene homopolymer; and T2) from 10 wt % to 50 wt % of a polymer composition made from or containing A) 5-35% by weight of a propylene homopolymer or a propylene ethylene copolymer; B) 20-50% by weight of a copolymer of ethylene and a C.sub.3-C.sub.8 alpha-olefin containing from 0.1% to 20% by weight of alpha-olefin units; and C) 30-60% by weight of a copolymer of ethylene and propylene containing from 25% to 75% by weight of ethylene units.